TYPO3 Core

The problem is that in typo3/sysext/form/Classes/Mvc/Persistence/FormPersistenceManager.php in the function loadMetaData() the content of the file is read 1:1. The following helped me to get the problem under control:

$yamlFileLoader = GeneralUtility::makeInstance(YamlFileLoader::class);
$yaml = $yamlFileLoader->load(Environment::getPublicPath() . $file->getPublicUrl());

Of course, this had to be included cleanly via dependency injection and also the setting of the path probably needs to be queried better. But with the use of the YamlFileLoader the problem can be solved.

Patch set 2 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73688

Patch set 3 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73688

Patch set 4 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73688

Patch set 5 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73688

Patch set 6 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73688

Patch set 7 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73688

Patch set 8 for branch main of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73688

Patch set 1 for branch 11.5 of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at https://review.typo3.org/c/Packages/TYPO3.CMS/+/73712